OSAHS

Snoring is the most frequently reported symptom in
OSAHS and is found in 70–95% of such patients.
Typically, the snoring may have been present for many
years but has increased with intensity over time and is
further exacerbated by nighttime alcohol consumption,
weight gain, sedative medications, sleep deprivation, or
supine position. Snoring may become so loud as to be
greatly disruptive to the bedpartner and is often a source
of relationship discord; in one report, 46% of patients slept
in a different room from their partners. The characteristic
snoring pattern associated with OSAHS is one of loud
snores or brief gasps alternating with 20- to 30-second periods
of silence. Because snoring is so common in the general
population (35–45% in men, 15–28% in women ), it is
a poor predictor of OSAHS; however, only 6% of patients
with OSAHS do not report snoring and its absence makes
OSAHS unlikely. Corroboration with bedpartners is
important as approximately 75% of patients who deny
snoring are found to snore during objective measurement.
Witnessed apneas are observed by up to 75% of bedpartners
and are the second most common nocturnal symptom
reported in OSAHS. Occasional apneas are normal
and do not cause symptoms; however, as the frequency of
apneas increases, a certain threshold may be exceeded which
results in symptomatic disease. This threshold is variable
and unique to each patient such that some patients with a
low Respiratory Disturbance Index (RDI) may be profoundly
symptomatic while others with frequent respiratory
events present with relatively few complaints. Particularly
in OSAHS of milder severity, the apneic episodes are usually
associated with maintenance of respiratory movements
and are terminated by loud snorts, gasps, moans, or other
vocalizations and sometimes with brief awakenings and
body movements. In more severe disease, cyanosis can
occur along with the cessation of respiratory movement
during the apnea which will often cause considerable distress
to the bedpartner. Body movements at the time of
arousals in severe OSAHS can be frequent and sometimes
violent. Patients themselves are rarely aware of the apneas,
vocalizations, frequent arousals, movements, or brief
awakenings, although the elderly are particularly sensitive
to the frequent nocturnal awakenings and will report
insomnia and unrefreshing sleep.
Nocturnal dyspnea, sometimes described by patients as
a sensation of choking or suffocating, has been observed in
18–31% of patients with OSAHS. These episodes typically
occur with arousal, are associated with feelings of panic
and anxiety, and generally subside within a few seconds.
During apneas or hypopneas, greater negative intrathoracic
pressures are generated as patients increase their inspiratory
efforts to overcome the upper airway obstruction.
This increases venous return to the heart and thus elevates
pulmonary capillary wedge pressure which produces the
sensation of dyspnea. Other important causes of paroxysmal
nocturnal dyspnea include left heart failure, nocturnal
asthma, acute laryngeal stridor, or Cheyne–Stokes respirations;
however, these episodes tend to be longer in duration
and may also occur during the daytime. Further investigation
may be warranted to differentiate OSAHS from these
other entities although they may also coexist.